HPV Vaccine: Early Evidence of Impact

June 17, 2011 -- Health officials in Australia are reporting what may prove to be the first evidence that the vaccine targeting the human papillomavirus (HPV) could prevent cervical cancer in a large population.

The incidence of lesions that lead to cervical cancer dropped dramatically among Australian teen girls after a nationwide, school-based HPV vaccination program was implemented in that country.

Between 2007 and 2009 -- the first three years of the program -- high-grade cervical abnormalities declined by 50% in Victoria, Australia, among girls aged 17 and younger.

Vaccine Effect? ‘Too Soon to Say’

Australia was the first country to implement population-wide HPV vaccination targeting girls in their teens and early 20s, with the goal of vaccinating all girls as they enter high school at age 12 or 13. A "catch-up" program also targets older teens and women in their early 20s.

Researchers are still working to determine if the decline in precancerous lesions among teen girls was limited to those who had been vaccinated, so it is too soon to say if it represents true evidence of a vaccine effect, epidemiologist Julia M. Brotherton, MD, MPH, tells WebMD.

“It certainly looks like this could be a vaccine effect, but until we are actually able to link vaccine registry data with Pap test data we can only speculate about that,” she says. “What we can say is that this is an exciting, early finding.”